Estimation of the influence of the regimes of heat treatment of products from photocured polymers, manufactured by laser stereolitography technology, on their physical and mechanical characteristics | Mekhanika | kompozitsionnykh | materialov i konstruktsii

Estimation of the influence of the regimes of heat treatment of products from photocured polymers, manufactured by laser stereolitography technology, on their physical and mechanical characteristics

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Abstract:

The influence of heat treatment of products obtained by laser stereolithography on their physical and mechanical characteristics is considered. It has been established that annealing of specimens from the cured Formlabs Standard White V04 photopolymer resin at 60oС for an hour leads to a significant increase in the modulus of elasticity and ultimate strength, which is confirmed by the results of standard tests. As an alternative to destructive tests to control the elastic and strength properties of articles made of hardened photopolymer resins, it is proposed to use the dynamic indentation method. Analytical expressions are given for calculating the hardness and elastic modulus of the materials under study by the main parameters of the recorded shock loading diagram. Based on the experimental data, the calibration dependences were obtained between the values of the ultimate strength and elastic modulus established during standard tests and the hardness and elastic modulus measured by the method of local impact deformation using a spherical indenter. It is shown that these dependences have a linear character and make it possible to measure the ultimate strength by the method of dynamic indentation with an error of no more than 4%, and the modulus of elasticity with an error of no more than 3% in the considered range of changes in properties. It has been established that the method of local impact deformation is sufficiently sensitive to changes in the physical and mechanical characteristics of cured polymeric materials caused by thermal action, and can be used both for debugging the technological modes of heat treatment of products obtained using SLA-technology and for operational control of their quality.

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